The present invention relates to a process for preparing biscuits containing glucomannan powder obtained by pulverizing glucomannan, a non-caloric carbohydrate, particularly that contained in a large amount in a tuberous root of devil's tongue (Amorphophallus konjac C. Koch) and then purifying the same. The glucomannan powder is obtained by, for example, extracting devil's-tongue powder with water under 1.5 atmos. or with a 10% liver oil solution, then adding Fehling's solution thereto to effect precipitation, then treating the precipitates with hydrochloric acid, filtering the precipitates and purifying the same by washing with ethanol.
It is common knowledge that the number of obese people is presently increasing. This increase is probably due to improvements in economic and food conditions from 1960 onward and changes in modes of living. It is considered that corpulence is undesirable for maintaining ones health and a graceful figure, particularly for women.
In recent years, glucomannan powder has been popularly used (for example, glucomannan powder is available on the market in an aluminum pack containing a dose thereof, which is stirred in water before use) as a means of body weight reduction for obese people. The glucomannan powder is essentially tasteless and odorless, but it cannot be taken easily by some people.
For overcoming these problems, the present inventor has previously proposed: (a) a confectionery containing glucomannan powder as the main component and which is prepared by packing a suitable amount of glucomannan powder air-tightly in a capsule of a desired shape, which capsule is made of edible gelatin, and coating the capsule with a suitable confectionery material to form an outer layer, (b) a confection mainly comprising glucomannan powder and an oil prepared by mixing a suitable amount of glucomannan powder with a suitable amount of an oil and coating the periphery of the mixture air-tightly with a layer of a confectionery material and (c) a confection mainly comprising glucomannan powder prepared by enclosing a suitable amount of glucomannan powder with a shell made of a confectionery material (see Japanese Utility Model Application Nos. 063,611/1979; 095,628/1979 and 128,545/1979). These confectioneries, are now made on an experimental basis and have been sampled to reveal that they can attain the intended purposes sufficiently.
However, in the confections of the prior applications, glucomannan powder is enclosed therein along or in the form of a mixture with an oil. In other words, glucomannan powder is not combined with flour which is indispensible for making ordinary confections (excluding candies). Confectionery made with glucomannan powder has not been accepted by the general public. A further improvement is desired for using glucomannan for a confection, though the confections of the prior applications are still far superior to the case wherein glucomannan is taken as powder.
It is an object of the present invention, therefore, to provide very palatable biscuits containing glucomannan.
Another object of the present invention is to provide a process for preparing biscuits containing glucomannan having the effects of glucomannan powder per se, i.e., satisfaction of appetite and inhibition of absorption of nourishments.
Still another object of the present invention is to provide a process for preparing biscuits containing glucomannan on a large scale and at a low cost, which biscuits can be easily stored and transported.